02 T&C alternator squeaking?

Yes it could be an idler pulley, yes it could be a chirping belt, yes it could be an ac compressor, but it really is very likely to be the alternators one way clutch/coupler. Give the pulley a twist back and forth and feel how it rotates after you compare to a new one you can see how much slop can develop. I used to work at a dodge dealer and we replaced many perfectly charging denso altnators on RS vans due to growling/squeaking/chirping/ratcheting clutches. I believe the reason that chrysler (and many other companies) installed that goofy little clutch on there is so that when the high load ac clutch kicks in there is something in the system with a little slip. I don't know that for a fact but I know that those clutches are now on toyota denso alternators as well.

My time at dodge convinced me to never buy anything made by chrysler from 1990-2009 except leftover models like rams and dakota. Any model changes made after 90 I wouldn't touch.